Glaucoma is an intractable ocular disease with a risk of blindness, involving the increase of intraocular pressure due to various factors and the disorder of internal tissues of eyeballs (retina, an optic nerve and the like). A general method of treating glaucoma is intraocular pressure reduction therapy, which is exemplified by pharmacotherapy, laser therapy, surgical therapy and the like.
For the pharmacotherapy, drugs such as sympathomimetic agents (nonselective stimulants such as epinephrine, α2 stimulants such as apraclonidine), sympatholytic agents (β-blockers such as timolol, befunolol, carteolol, nipradilol, betaxolol, levobunolol and metipranolol and α1-blockers such as bunazosin hydrochloride), parasympathomimetic agents (pilocarpine and the like), carbonic anhydrase inhibitors (acetazolamide and the like) and prostaglandins (isopropyl unoprostone, latanoprost, travoprost, bimatoprost and the like) have been used.
Recently, a Rho kinase inhibitor was found to serve as a therapeutic agent for glaucoma based on a new mechanism of action (WO 00/09162). Invest. Ophthalmol. & Vis. Sci., 42 (1), 137-144 (2001) discloses that the Rho kinase inhibitor increases the aqueous humor outflow from a trabecular meshwork outflow pathway thereby reducing intraocular pressure, and Invest. Ophthalmol. & Vis. Sci., 42 (1), 137-144 (2001) and Invest. Ophthalmol. & Vis. Sci., 42 (5), 1029-1037 (2001) suggest that the action is due to a change of cytoskeleton in trabecular meshwork cells.
Combined use of drugs having actions of reducing intraocular pressure to treat glaucoma has already been studied and there are some reports on the studies. For example, Japanese Patent No. 2726672 reports combined administration of the sympatholytic agent with prostaglandins. WO 02/38158 discloses a method of treating glaucoma by administering some drugs having actions of reducing intraocular pressure in combination to eyes.
However, any reports do not describe the Rho kinase inhibitor at all, and naturally, there is no description concerning advantageous effects brought about by combining the Rho kinase inhibitor with a β-blocker, either.
As mentioned above, neither study nor report has been made concerning therapeutic effects on glaucoma obtained by combining the Rho kinase inhibitor with the β-blocker, so far.